Well curing operation between simultaneously formed bores



p 1%? o. J. M CULLOUGH WELL CURING OPERATION BETWEEN SIMULTANEOUSL'Y FORMED BORES 3 Sheets-Sheet 1 Filed March 13, 1964 INVENTOR.

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WELL CURING OPERATION BETWEEN SIMULTANEOUSLY FORMED BORES Filed March 5 Sheets-Sheet 2 INVENTOR.

WHANN a McMA/WGWL A/Iorneys for A a 07km?! Offs Johnson Mo [Erika/ Aprifl 3957 o. J. M CULLOUGH WELL CURING OPERATION BETWEEN SIMULTANEOUSLY FORMED BORES 3 Sheets-Sheet 5 Filed March 13, 1964 07 /5 Jo/waon Mfufiozy/ INVENTOR.

M w. WIW A mm WW w, m W A United States Patent @fifice 3,313,351 Patented Apr. 11, 1967 3,313,361 WELL CUIJNG OPERATION BETWEEN SEIULTANEQUSLY FORD 1E1) BORES Otis .iohnson McCuilough, PA). Box 2575, Houston, Tex. 77001 Filed Mar. 13, 1964, Ser. No. 351,770 2 Claims. (Cl. 175-61) This invention relates generally to the drilling of bore holes in the earth and relates more particularly to a drilling method and means for drilling wells and the like.

While the invention has particular utility in connection with the drilling of oil wells and the like, and is shown and described in such connections, it is to be understood that its utility is not confined thereto.

Various problems and dificulties are encountered in the drilling of well bores into the earth, particularly in the drilling of deep wells, and it is an object of the present invention to provide method and means for solving said problems and overcoming the difliculties involved therein.

in its broader aspects, the invention contemplates a method involving the simultaneous drilling of at least two wells located adjacent to each other and, should one well become disabled, using fluid from the other well to help the disabled well out of its difiiculty.

it is another object of the invention to provide a method which involves simultaneously drilling at least two wells located adjacent to each other and interconnecting at subsurface level during drilling operations to remedy trouble that may occur in one or the other of said wells.

It is still another object of the invention to provide a method for drilling a plurality of generally parallel well bores at convenient distances from each other, and should drilling of one bore run into difficulty the other bore is deflected into this bore, and in which circulating or treating fluid is delivered to the bore in difficulty at an appropriate elevation.

it is a still further object of the invention to provide a method of simultaneously drilling a plurality of wells and whipstocking between them, thus enabling one well to assist another well.

It is another object of the invention to provide a method of this character whereby fluid under pressure may be delivered to the disabled well from the other well above or below the disabled portion and auxiliary pressure may, therefore, be applied in a downward direction or in an upward direction in said disabled well.

it is still another object of the invention to provide a drilling method of this character wherein different fluids may be introduced to a well at selected locations so that auxiliary pressure may be applied in an upward direction with respect to the disabled portion or in a downward direction.

It is another object of the invention to provide a method of this character wherein, after the disability in the one well has been cured, normal drilling is continued in both wells until the desired oil bearing formations are reached or it is decided to abandon the wells.

The characteristics and advantages of the invention are further sufiiciently referred to in connection with the following detailed description of the accompanying drawings, which represent certain embodiments. After considering these examples skilled persons will understand that variations may be made without departing from the principles disclosed and I contemplate the employment of any structures, arrangements or modes of operation or steps of the method that are properly within the scope of the apppended claims.

Referring more particularly to the drawings, which are for illustrative purposes only:

FIG. 1 is a schematic or diagrammatic view showing a pair of oil wells showing how deflected or lateral bores may be drilled from either well to the other;

FIG. 2 is a schematic or diagrammatic view of a pair of oil wells being drilled in accordance with the present method;

FIG. 3 is a schematic or diagrammatic view showing an alternative drilling program in accordance with the present invention;

FIG. 4 is a schematic or diagrammatic view of another alternative arrangement; and

FIG. 5 is an enlarged schematic sectional view through a packer used in the present invention.

Referring more particularly to FIG. 1 of the drawings, there is schematically shown a pair of wells, indicated generally at 10 and 11, respectively, with some of the drilling equipment. Well known drilling equipment is used, including derricks, indicated generally at 12 and 14, respectively, which have rig floors 15 and 16, respectively, and the usual rotary tables 17 and 18.

Well bores 19 and '20 are drilled simultaneously with the usual drilling equipment, including drill strings or pipes 21 and 22, the depth of the two wells being maintained substantially the same during the drilling operation. As is the usual practice, the well bores are drilled in progressively smaller diameters with increasing depths, as best shown in FIGS. 1 and 4.

Both wells 10 and 11 have surface casing or pipe indicated respectively at 24 and 25. This surface pipe may run to any suitable depth. For example, in a deep well there may be up to approximately 3,000 feet of surface pipe, and sometimes in such a deep well there would be another string on the inside of the surface casing which may run to any suitable depth, such as, for example, 5,000, 6,000 or 7,000 feet. In FIG. 1 the second string of pipe is indicated at 26 and 27 for the respective wells 10 and 11.

Gften there is another string of pipe reaching down from the surface to 10,000, 12,000 and even 15,000 or 18,000 feet, the latter strings of pipe being indicated at 28 and 29, respectively, for the wells 10 and 11. From the lower end of the pipe strings 28 and 29 drilling may be in open hole, as at 30 and 31, respectively.

A well may, of course, get into difficulty at almost any point, at least after the hole has been drilled to a substantial depth.

In FIG. 2 well 10 is shown in difliculty, the pipe string 21 being stuck in a keyseat, indicated generally at 35, said pipe string or drill string having a bit 36 operably attached to the lower end thereof.

As may sometimes occur, the hole may be drilled crooked, as at 37, and as the drilling continues the pipe string 21 works over into the formation portion or keyseat 33, which is one of the well known situations where the drill string or pipe gets stuck. Under these conditions the bit 36 may be anywhere, for example, from feet to 3,000 or 4,000 feet, below the keyseat.

After the drill string 21 has become stuck and cannot be freed with an upward pull on said string, it is cut off above the point where it is stuck. Any well known method for cutting the pipe may be used, such as, for example, mechanical cutters, jet or chemical cutters, any of which method or means are well known in the art.

The pipe above the the cutoff, indicated generally at 40, is recovered in the usual well known manner and a string of pipe 41 with an overshot 42 is run back into the hole and manipulated so that the overshots will go over the fish or pipe that has been cut off and remains in the hole. Once the overshot has taken a firm hold on the fish a pulling force may be applied.

Along with the cutting off and recovery of the pipe above the cutoff and the attaching of the overshot to the fish, a lateral or connecting bore 44 is drilled from the bore of the well 11. In drilling the connecting bore 44 any suitable well known deflection tools may be used. As shown in FIG. 2, a whipstock 46 is positioned in the usual well known manner at the proper depth of the bore of the well 11, the particular whipstock shown being that of the Eastman Oil Well Survey Company, although any other suitable well known type of whipstock may be used. Other bore hole deflection tools may also be used, such as, for example, the Eastman Oil Well Survey Companys turbodrill used with bent sub or their jetting technique for soft formations.

Drilling of the connecting or lateral bore 44 is effected with a bit 47 at the lower end of a drill string 48. The opening from the bore of well 11 into the connecting bore 44 is indicated at 49 and the point of connection with the bore of the well is at 50 below the bit 36 in said bore of well 10.

With the completion of the connection between the bore of well 11 and the bore of the well 10 below the bit 36 the string 48 with its bit 47 is removed from well 11. A mechanical pulling force is then applied to the fish and at the same time fluid pressure is applied to the underside of the bit, said fluid being pumped down the bore of well 10, through the lateral or transverse bore 44 and into the bore of well 10 below said bit 36. The fluid from well 11 returns to the surface through the bore of the Well 10.

After the difliculty in well 10 is overcome the whipstock 46 is removed and drilling is continued in both wells simultaneously, the depth of said wells being maintained substantially the same.

Under some conditions it might be found desirable or necessary to apply fluid pressure from the well 11 both above and below the bit 36. Such an arrangement is shown in FIG. 3, wherein there is a second connecting or lateral bore, indicated at 55, between the bore of the well '11 and the bore of the well 10. This lateral bore may be drilled in substantially the same rway as the connecting bore 44 or by any other suitable means. Lateral bore 55 branches from the bore of well 11 at the point 56 and connects with the bore of the well 10 at 57 above the bit 36 of the latter well.

Should it be found necessary to provide two connecting bores, such as bores 44 and 55, connecting the bore of well :11 with the bore of well 10, both below and above the bit 36 in the latter well, the drill string and other tools are removed from the bore of the well 11 and a packer 58 at the lower end of the pipe string 59 is lowered to a location between the entrance 49 of the connecting bore 44 and the entrance of the connecting bore 55. The packer is of a resilient material and is of the expandable type, being operably disposed on the string 59. Pressure fluid is supplied to the interior 60 of said packer by a conduit 56 which extends to the upper end of the well 11 and is connected to any suitable source, not shown, of fluid under pressure. The packer is expanded by the fluid pressure therein and fluid under pressure is then pumped down through the pipe string 59 and into the bore of well 11 below the packer. This fluid under pressure is also conducted through the connecting bore 44 to the bore of well 10 below the bit 36. Pressure is thus applied to the under side of the bit and fluid above the bit may return to the surface of well 11 by way of the connecting bore '55, the pressure fluid from the connecting bore 55 being conducted upwardly in the bore of well 11 through the annular space about the pipe string 59 in the bore of said well 11. A reversal of this process may be effected if required. Fluid under pressure may be pumped down the annulus between the string 59 and the wall of the bore of well 11 above the packer 58, thence through the connecting bore 55 and into the bore of the well 10 above the bit 36 therein. The fluid pressure from the well 11 4 may be used to supplement fluid pressure from the upper end of well 10 and fluid below the bit 36 will flow through the connecting bore 44, into the bore of well 11 below the packer 5S thence to the top of well 11 through said string 59.

Trouble may, of course, occur in either well at almost any point of drilling. Whichever well becomes disabled may be helped out by fluid from the other well. In FIG. 1 there are shown lateral or connecting bores from well 11 to well 10, said connecting bores being indicated at and 66. There are similar connecting bores from well It) to well 11 as indicated at 67 and 63. The connecting across of lateral bores shown in FIG. 1 does not necessarily mean that all of such connecting bores would be used during a drilling program. These connecting bores are shown to bring out the fact that such connecting bores may be drilled from either well to the other and at various depths, depending on the point of trouble in a disabled well.

In FIG. 4 three wells are shown and are indicated generally at 7 9, 71 and 72. These wells have respective bores 73, 74 and 75. Various lateral connecting bores may be drilled from any of these wells to any other of said wells, as required. For example, lateral bores 76 and 77 are shown as drilled from the bore 74 of well 71 to the bore 73 of well 70. Lateral connecting bores 78 and 79 are shown as having been drilled from the bore 74 of well 71 to the bore 75 of well 72. There are also shown lateral connecting bores 80 and 81 from the bore 73 of well 70 to the bore 74 of well 71. A connecting bore 82 is shown as leading from the bore 75 of well 72 to the bore 74 of well 71. Only one such lateral connecting bore is shown between these wells although it is to be understood that any number of such bores may be drilled. There is also a lateral connecting bore 83 from the bore 75 of well 72 to the bore 73 of well 70 and a lateral connecting bore 84 from the bore 73 of well 70 to the bore 75 of well 72.

It is to be understood, of course, that the lateral connecting bores described above are drilled to meet particular situations when a well becomes disabled. Conceivably, a drilling program could be conducted Without a well getting into dificulty, but the probability is that in the drilling of very deep wells a well would become dis abled and the present invention provides for the helping of a disabled well out of difficulty with fluid from another well.

The invention and its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the parts of the invention without departing from the spirit and scope thereof or sacrificing its material advantages, the arrangement hereinbefore described being merely by way of example and I do not wish to be restricted to the specific form shown or uses mentioned except as defined in the accompanying claims, wherein various portions have been separated for clarity of reading and not for emphasis.

I claim:

1. A method for drilling for oil and the like, comprising:

(A) drilling a pair of wells simultaneously and maintaining the depth of the wells substantially the same during the drilling operation;

(B) circulating fluid from one well to the other well when a drill string becomes stuck in the bore of the other well and circulating said fluid back to the first well to create a flow of fluid around at least a part of said stuck drill pipe;

(C) while simultaneously conducting an operation through said one well to free said stuck drill pipe;

(D) and thereafter completing drilling operations in at least one of said wells.

2. A method for drilling for oil and the like, comprising:

(A) drilling a pair of wells simultaneously and main taining the depth of the Wells substantially the same during the drilling operations;

(B) drilling a plurality of lateral bores from one of the wells to the other when a drill string with a bit at the lower end becomes stuck in the bore of the other Well, one of said lateral bores communicating with said other Well below the bit and the other of said lateral bores communicating with said other Well above the bit;

(C) installing a barrier in said one Well between the openings into the respective lateral bores from said one Well;

(D) circulating fluid under pressure in a circuit including a part of the disabled Well and said lateral bores;

(E) While simultaneously conducting operations through said one well to free said stuck drill pipe;

(F) and conducting further drilling operations in both wells at a greater depth after the disabled well has been cured.

References Cited by the Examiner UNITED STATES PATENTS OTHER REFERENCES The Petroleum Handbook, 3rd edition, 1948, The Shell 15 Petroleum Co., Ltd., page 100 relied on.

ERNEST R. PURSER, Primaly Examiner. 

1. A METHOD FOR DRILLING FOR OIL AND THE LIKE, COMPRISING: (A) DRILLING A PAIR OF WELLS SIMULTANEOUSLY AND MAINTAINING THE DEPTH OF THE WELLS SUBSTANTIALLY THE SAME DURING THE DRILLING OPERATION; (B) CIRCULATING FLUID FROM ONE WELL TO THE OTHER WELL WHEN A DRILL STRING BECOMES STUCK IN THE BORE OF THE OTHER WELL AND CIRCULATING SAID FLUID BACK TO THE FIRST WELL TO CREATE A FLOW OF FLUID AROUND AT LEAST A PART OF SAID STUCK DRILL PIPE; 